LOCATION DESMET MTEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, frigid Calcidic Haploxerolls
TYPICAL PEDON: Desmet loam, in cropland. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 7 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium granular structure; slightly hard, very friable, slightly sticky, and slightly plastic; many fine roots; common fine pores; neutral (pH 7.0); abrupt smooth boundary. (5 to 10 inches thick)
A2--7 to 15 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate coarse subangular blocky structure; slightly hard, very friable, slightly sticky, and slightly plastic; many fine roots; many fine pores; slightly alkaline (pH 7.5); clear wavy boundary. (6 to 10 inches thick)
Bk--15 to 24 inches; light gray (2.5Y 7/2) loam, dark grayish brown (2.5Y 4/2) moist; weak medium and coarse subangular, blocky structure; slightly hard, very friable, slightly sticky, and slightly plastic; common soft masses of lime; strongly effervescent; moderately alkaline (pH 8.0); gradual smooth boundary. (8 to 24 inches thick)
BC--24 to 60 inches; light gray (2.5Y 7/2) very fine sandy loam, grayish brown (2.5Y 5/2) moist; massive; slightly hard, very friable, nonsticky, nonplastic; few fine roots; few fine pores; disseminated lime; strongly effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Missoula County, Montana; 600 feet south and 120 feet east of the NW corner of sec. 34, T. 12 N., R. 20 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 45 to 47 degrees F.
Moisture control section - approximately between the depths of 4 and 12 inches
Mollic epipedon thickness - mainly 7 to 15 inches
Control section - 10 to 18 percent clay
Depth to Bk horizon - 11 to 20 inches
Ap horizon - (Uncultivated pedons have a thin A1 horizon.) Value: 2 or 3 moist
Clay content: 10 to 18 percent
Reaction: pH 6.6 to 7.8
A2 horizon - Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3
Texture, less than 2 mm: loam or very fine sandy loam
Clay content: 10 to 18 percent
Reaction: pH 7.4 to 8.4
Bk horizon - Hue: 10YR or 2.5Y
Value: 5, 6, 7, or 8 dry; 4, 5, or 6 moist
Chroma: 2 or 3
Texture, less than 2 mm: loam, silt loam, or very fine sandy loam Clay content: 10 to 18 percent
Calcium carbonate equivalent: 8 to 15 percent
Reaction: pH 7.4 to 8.4
BC horizon - Hue: 10YR or 2.5Y
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 2 or 3
Texture, less than 2 mm: very fine sandy loam (fine sandy loam textures occur below a depth of 39 inches)
Clay content: 10 to 18 percent
Rock fragments: 0 to 15 percent pebbles
Calcium carbonate equivalent: 5 to 12 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES: These are the Ammon and Newdale series. Ammon soils are calcareous throughout the profile. Newdale soils have 15 to 30 percent calcium carbonate equivalent in the calcic horizon.
GEOGRAPHIC SETTING: Desmet soils are on terraces in intermountain valleys. Elevations are 2,800 to 3,500 feet. Slopes are 0 to 2 percent. These soils formed in alluvium. The climate is characterized by long, cold winters, moist springs; and warm, dry summers. Mean annual precipitation is 11 to 14 inches, much of which falls as snow or as spring rain. Mean annual temperature is 43 to 45 degrees F. The frost-free period is 105 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Moiese and Grantsdale soils. Moiese soils are sandy-skeletal. Grantsdale soils coarse-silty over sandy or sandy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: Desmet soils are used for irrigated and dryland crops, as pastureland, and for urban development.
DISTRIBUTION AND EXTENT: Desmet soils are of small extent in mountain valleys of western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Missoula County, Montana, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 15 inches (Ap, A horizons); soft secondary lime within 43 inches of the surface (Bk horizon); particle-size control section from 10 to 40 inches. Desmet soils have an aridic moisture regime that borders on xeric and a frigid temperature regime.
ADDITIONAL DATA: Reference laboratory data 6/79 available. National Soil Survey Laboratory Number 79T7359.